Now we can use the predefined transaction formats, e.g. Transfer or
limit_order_create as follows:

define the expiration time

define a JSON object that contains all data for that transaction

load that data into the corresponding operations class

collect multiple operations

get some blockchain parameters to prevent replay attack

Construct the actual transaction from the list of operations

sign the transaction with the corresponding private key(s)

Example A: Transfer

expiration=transactions.formatTimeFromNow(60)op=operations.Transfer(**{"fee":{"amount":0,"asset_id":"1.3.0"},# will be filled in automatically"from":"1.2.124","to":"1.2.1241","amount":{"amount":10000,"asset_id":"1.3.0"},})ops=[transactions.Operation(op)]ref_block_num,ref_block_prefix=transactions.getBlockParams(rpc)tx=transactions.Signed_Transaction(ref_block_num=ref_block_num,ref_block_prefix=ref_block_prefix,expiration=expiration,operations=ops)tx=tx.sign([wif])

Example A: Limit-order-create

# Expiration time 60 seconds in the futureexpiration=transactions.formatTimeFromNow(60)op=operations.Limit_order_create(**{"fee":{"amount":100,"asset_id":"1.3.0"},"seller":"1.2.29","amount_to_sell":{"amount":100000,"asset_id":"1.3.0"},"min_to_receive":{"amount":10000,"asset_id":"1.3.105"},"expiration":"2016-05-18T09:22:05","fill_or_kill":False,"extensions":[]})ops=[transactions.Operation(op)]ref_block_num,ref_block_prefix=transactions.getBlockParams(rpc)tx=transactions.Signed_Transaction(ref_block_num=ref_block_num,ref_block_prefix=ref_block_prefix,expiration=expiration,operations=ops)tx=tx.sign([wif])